Methods and systems for dosing control in an automated fluid delivery system

ABSTRACT

Methods and systems for dispensing a fluid using an automated fluid delivery system are disclosed. A pump may be configured to force an aliquot of fluid into a fluid delivery channel. A processor may receive values of a property for the aliquot and the source of the aliquot. The processor may use the values to determine the volume of the aliquot. The determined volume is compared by the processor against an expected volume to establish the amount of fluid being pumped by the pump per unit, such as time or revolutions. The processor controls operation of the pump to dispense a predetermined dose based on the amount of fluid being pumped by the pump per unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 14/825,568, filedAug. 13, 2015, now U.S. Pat. No. 9,375,528, which is a Continuation ofU.S. Ser. No. 13/784,615, filed Mar. 4, 2013, now U.S. Pat. No.9,109,591, the disclosures of each of which are incorporated herein bythis reference.

BACKGROUND

Automated fluid delivery systems, such as infusion systems, operate toadminister medication to a patient in carefully measured doses. Suchinfusion systems may deliver fluids in a manner that is often more costeffective and reliable than if performed manually by medical staff.Accurate dosing is important, especially for particular fluids, such asradiopharmaceuticals where high precision is required to ensure that thepatient is not exposed to too much radioactive material. Typicalautomated infusion systems pump the fluid using an infusion pump througha delivery tube and into a patient's venous system through a needle orcatheter. A common infusion pump is the peristaltic pump that operatesby deforming the delivery tube to force the fluid from a fluid sourcetoward the patient.

The automated infusion process is often controlled using variousparameters, such as infusion rate and duration, dose volume, patientweight, and medication units and concentration. However, theseparameters are affected by the specific components and operatingcharacteristics of the infusion system equipment. Conventional automateddosing techniques do not adequately adjust for these variances, whichmay lead to inaccurate delivery of medical fluids to patients.

SUMMARY

The invention described in this document is not limited to theparticular systems, methodologies or protocols described, as these mayvary. The terminology used herein is for the purpose of describingparticular embodiments only, and is not intended to limit the scope ofthe present disclosure.

It must be noted that as used herein and in the appended claims, thesingular forms “a,” “an,” and “the” include plural reference unless thecontext clearly dictates otherwise. Unless defined otherwise, alltechnical and scientific terms used herein have the same meanings ascommonly understood by one of ordinary skill in the art. As used herein,the term “comprising” means “including, but not limited to.”

In an embodiment, a system for dispensing a fluid may comprise a pumpconfigured to force an aliquot of fluid from a fluid source into a fluiddelivery channel and at least one sensor configured to measure a samplevalue of a property of the aliquot. A computing device in communicationwith the pump and the at least one sensor may comprise a processor and anon-transitory, computer-readable storage medium in operablecommunication with the processor. The computer-readable storage mediummay contain one or more programming instructions that, when executed,cause the processor to: receive the sample value, receive a source valueof the property for the fluid source, determine a sample volume of thealiquot based on a comparison of the sample value and the source value,and control operation of the pump to dispense a predetermined dose ofthe fluid based on a comparison of the sample volume with an expectedvolume.

In an embodiment, a method of dispensing a fluid may comprise providinga pump configured to force an aliquot of fluid from a fluid source intoa fluid delivery channel. A processor may receive a source value of aproperty for the fluid source and a sample value of the property for thealiquot measured by at least one sensor. The processor may determine avolume of the aliquot based on a comparison of the sample value of theproperty and the source value of the property. The operation of the pumpmay be controlled by the processor to dispense a predetermined dose ofthe fluid based on a comparison of the sample volume with an expectedvolume.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an illustrative automated fluid delivery system accordingto an embodiment.

FIG. 2 depicts an illustrative peristaltic pump that may be used inautomated fluid delivery systems configured according to someembodiments.

FIG. 3 depicts illustrative fluid delivery channels having differentdimensional properties.

FIG. 4 depicts an illustrative automated fluid delivery system controlscreen according to some embodiments.

FIG. 5 depicts a flow diagram of a method of dispensing a fluidaccording to an embodiment.

FIG. 6 depicts a block diagram of illustrative internal hardware thatmay be used to contain or implement program instructions according to anembodiment.

DETAILED DESCRIPTION

The terminology used in the description is for the purpose of describingthe particular versions or embodiments only, and is not intended tolimit the scope.

The present disclosure is directed toward dosage control in an automatedfluid delivery system, such as an automated infusion system. In oneembodiment, a fluid delivery pump is used to pump a fluid beingdelivered to a patient through the automated fluid delivery system. Anillustrative and non-restrictive example of a fluid delivery pump is aperistaltic pump. According to some embodiments, the automated fluiddelivery system may compare a property of the fluid in a fluid sourcewith the same property of the fluid in a fluid delivery channel of theautomated fluid delivery system. This comparison may be used todetermine the sample volume of the fluid in the fluid delivery channel.This volume may be compared with an expected or standard volume tocorrelate operation of the pump with volume of the fluid pumped into thefluid delivery channel. The automated fluid delivery system may operateto control the pump based on this comparison. In an embodiment, theautomated fluid delivery system may be configured to deliver aradiopharmaceutical. In this embodiment, the property may compriseradioactivity of a volume of the radiopharmaceutical. A non-limitingexample of an automated fluid delivery system is the Intego™ positronemission tomography (PET) infusion system provided by Bayer MedicalCare, Inc. of Indianola, Pa.

FIG. 1 depicts an illustrative automated fluid delivery system accordingto an embodiment. As shown in FIG. 1, an automated fluid delivery system100 may include a fluid delivery apparatus 105 configured to deliver amedical fluid to a patient. In an embodiment, the fluid deliveryapparatus 105 may comprise an infusion apparatus. The fluid deliveryapparatus 105 may have a medical fluid source 130 arranged therein andconfigured to hold a volume of the medical fluid. For example, somediagnostic imaging procedures, such as PET and single-photon emissioncomputed tomography (SPECT), require that a patient receive radioactivecontrast agents, also called radiopharmaceuticals, to obtain images. Ina radiopharmaceutical infusion system, the medical fluid source 130 maybe in the form of a shielded vial or “pig,” such as a tungsten shieldedvial. In another example, the medical fluid source 130 may comprise aninfusion bag, such as an intravenous (IV) bag. Embodiments provide thatthe medical fluid may comprise any fluid capable of being delivered to apatient through an automated fluid delivery system, including, withoutlimitation, saline, chemotherapy drugs, radiopharmaceuticals, andcontrast agents.

The medical fluid source 130 may be in fluid communication with a pump115 through a fluid delivery channel 135. Although the medical fluidsource 130 is depicted in FIG. 1 as being located within the fluiddelivery apparatus 105, embodiments are not so limited. The medicalfluid source 130 may be located outside of the fluid delivery apparatus105 in fluid communication with the fluid delivery apparatus through thefluid delivery channel 135. Accordingly, the fluid delivery channel 135may be located at least partially outside of the fluid deliveryapparatus 105. Some embodiments provide that the fluid delivery channel135 may include more than one section and the sections may havedifferent characteristics. For example, the fluid delivery channel 135may be made of one type of material and have a particular diameter,thickness, or other property at a certain section and may be made ofanother material and/or have a different diameter, thickness, or otherproperty at a different section.

Operation of the pump 115 draws the fluid out of the medical fluidsource 130 and pumps it toward a dispensing element 120. Embodiments maybe configured to operate with any type of pump known to those havingordinary skill in the art or that may be developed in the future thatmay operate as described herein. Illustrative pumps include, withoutlimitation, turbine pumps, peristaltic pumps, diaphragm pumps, screwpumps, syringe pumps, and centrifugal pumps. The dispensing element 120may be configured to deliver the medical fluid to a patient through thefluid delivery channel 135, such as a needle or catheter.

A controller 125 may be in communication with the pump 115. Thecontroller 125 may generally comprise a processor, a non-transitorymemory or other storage device for housing programming instructions,data or information regarding one or more applications, and otherhardware, including, for example, the central processing unit (CPU) 605,read only memory (ROM) 610, random access memory 615, communicationports 640, controller 620, and/or memory device 625 depicted in FIG. 6and described below in reference thereto. The controller 125 may beconfigured to receive information from the pump 115, such as the speedof the pump. Certain aspects of the pump 115 may be directed by thecontroller 125, such as the number of rotations, speed, linear traveldistance, and/or active status (e.g., on/off, energized/de-energized,active/idle, etc.). In an embodiment, the controller 125 may executepump control software configured to control operation of the pump 115.For example, the control software may be configured to operate the pumpfor a specified amount of time, number of rotations, or linear traveldistance to displace a particular volume of the medical fluid.

The fluid delivery apparatus 105 may be operatively coupled with acomputing device 110. Embodiments provide that the computing device 110may comprise the illustrative internal hardware depicted in FIG. 6 anddescribed below in reference thereto. In an embodiment, the computingdevice 110 comprises a pump controller. In another embodiment, thecomputing device 110 comprises a stand-alone computing device incommunication with the fluid delivery apparatus 105. The computingdevice 110 may be configured to store or access data associated withoperation of the fluid delivery apparatus 105, such as patientinformation, medical fluid information, and operational information ofapparatus components. The data may be stored in one or more databases onthe computing device 110 and/or in a medical information systemaccessible by the computing device.

In an embodiment, the computing device 110 may execute one or moresoftware programs (e.g., control software) for operating the fluiddelivery apparatus 105. For example, the one or more software programsmay present a user interface on a display device (not shown) connectedto the computing device 110 for medical staff operation of the fluiddelivery apparatus 105. For instance, an operator may start and/or stopinfusion and view information associated with the infusion process fromthe user interface. An illustrative user interface is depicted in FIG. 4and described in more detail below. According to some embodiments, thecomputing device 110 may be in communication with the controller 125.The computing device 110 may receive information from the controller125, such as pump control information, and may provide for operatorcontrol of the pump 115 directly or through the controller 125. In anembodiment, the control software may operate to control the automatedfluid delivery system and/or components thereof. For instance, thecontrol software may be configured to direct the controller 125 and/orthe pump 115 to operate for a specified amount of time, number ofrotations, linear travel distance, or any other type of pump operationcapable of controlling the displacement of a particular volume of themedical fluid.

One or more sensors 140 may be positioned in and/or around the fluiddelivery apparatus 105 to obtain information associated with the medicalfluid. The one or more sensors 140 may be positioned at various places,such as in or around the medical fluid source 130, the fluid deliverychannel 135, or any other location suitable to obtain information aboutthe medical fluid as it travels through the fluid delivery apparatus105. The one or more sensors 140 may include any type of sensor capableof measuring a property of interest, including, without limitation,concentration, radioactivity, salinity, conductance, optical properties,analyte concentration, and combinations thereof. Illustrative sensorsinclude, but are not limited to, temperature sensors, pressure sensors,radioactivity sensors, optical sensors, analyte sensors, concentrationsensors, flow sensors, and combinations thereof. The computing device110 and/or the controller 125 may be in communication with the one ormore sensors 140 such that they may receive information detected by theone or more sensors, for example, for use by software applicationsexecuting on the computing device and/or the controller.

According to some embodiments, information obtained from the one or moresensors 140 (e.g., “sensor information”) may be used alone or incombination with other available information to determine propertiesabout the medical fluid being dispensed by the fluid delivery apparatus105. This information may be used to determine, for instance, whetherthe correct dose of the medical fluid is being dispensed to a patient.In one embodiment, the sensor information may be used in combinationwith fluid data, such as historical data or data calculated by one ormore software programs being executed by the computing device 110. In anembodiment, the sensor information may comprise information about themedical fluid in the fluid delivery channel 135 and the fluid data maycomprise information about the medical fluid in the medical fluid source130 or historical data relating thereto.

Embodiments described herein may include automated fluid deliverysystems, such as an automated fluid delivery system, comprising varioustypes of pumps. FIG. 2 depicts an illustrative peristaltic pump that maybe used in automated fluid delivery systems according to someembodiments. As shown in FIG. 2, a peristaltic pump 205 may include apump casing 210 housing a rotor 235. A fluid delivery channel 225 mayenter the pump casing 210 through an inlet 215, coil around the insideof the pump casing, and exit through an outlet 220. In an embodiment,the fluid delivery channel 225 may comprise a flexible and deformabletube, such as a polyvinyl chloride (PVC) tube. The fluid deliverychannel 225 may be in fluid communication with a source of a medicalfluid (not shown) on the inlet 215 side and a fluid dispensing unit (notshown) on the outlet 220 side.

The rotor 235 may be connected to a roller 240 that rotates with therotor. The roller 240 may be in contact with the fluid delivery channel225 within the pump casing 210, compressing the fluid delivery tube atthe point of contact. This compression in combination with the rotationof the rotor 235 forces the medical fluid through the fluid deliverychannel 225 from the inlet 215 toward the outlet 220. Embodiments arenot limited to the particular rotor 235 and roller 240 configurationdepicted in FIG. 2, as other peristaltic pump rotors may operateaccording to embodiments described herein. For example, the rotoritself, or one or more portions thereof, may be configured to be incontact with a fluid delivery channel in a manner similar to the roller240 depicted in FIG. 2. In another example, the rotor 235 and/or theroller 240 may include fins, rollers or other components configured toprovide smooth compression and fluid delivery through the fluid deliverychannel 225.

The amount of fluid progressing through the fluid delivery channel 225is dependent on, among other things, the rotational speed of the rotor235, degree of rotation or number of rotations of rotor 235, and thecross-sectional area of the fluid delivery channel. In some instances,pumping efficiency may be related to occlusion of the fluid deliverychannel 225, which may be a function of the wall thickness of the fluiddelivery channel and the minimum gap between the rotor and the interior230 of the pump casing 210. In a conventional medical infusion system,the speed of the fluid delivery pump, or infusion pump, may be fixed asit is generally assumed that the dimensional properties of the fluiddelivery channels do not vary appreciably across manufacturers or evenwithin the same manufacturer. Illustrative dimensional properties thatmay vary between different fluid delivery channels include outerdiameter, wall thickness and inner diameter. In addition, processvariation in the production of a fluid delivery channel may also lead tovariability in properties thereof. As such, dimensional properties mayvary along the length of the fluid delivery channel itself. Changes inthese properties will have an effect on the amount of medical fluiddelivered through the fluid delivery channel for a given speed and/orrotational distance of the pump rotor. Such process variation may leadto significant errors in fluid volume delivery, especially for finecontrol of small volumes of medical fluid.

FIG. 3 depicts illustrative fluid delivery channels having differentdimensional properties. As shown in FIG. 3, fluid delivery channels 305,310, 315 may have different dimensional properties, such as wallthickness, inner diameter, and outer diameter. For instance, a fluiddelivery pump of an automated fluid delivery system may have beendesigned to operate with the “standard” outer diameter 330 and innerdiameter 335 of fluid delivery channel 310. In addition, the controlsoftware of the automated fluid delivery system may have been configuredto control the fluid delivery pump with a fluid delivery channel havingsuch standard dimensional properties. The thickness of a fluid deliverychannel may be calculated by (outer diameter−inner diameter)/2 and thecross-sectional area may be calculated by π((inner diameter)/2)². Theamount of fluid pumped through a fluid delivery channel will be affectedby the thickness and cross-sectional area thereof. For instance, for anautomated fluid delivery system using a peristaltic pump, such as theperistaltic pump depicted in FIG. 2, the thickness of the fluid deliverychannel may affect the amount of compression by the rotor or roller. Thecross-sectional area may affect the volume of fluid travelling throughthe fluid delivery channel for a given pump speed.

Fluid delivery channel 305 may have the same inner diameter 325 asstandard fluid delivery channel 310, but may have a greater outerdiameter 320. As such, fluid delivery channel 305 may have the samecross-sectional area, but will have a different thickness. Fluiddelivery channel 315 may have a greater inner diameter 345 and a smallerouter diameter 340 than standard fluid delivery channel 310.Accordingly, fluid delivery channel 315 may have a greatercross-sectional area and a smaller thickness than standard fluiddelivery channel 305. The variability of fluid delivery channeldimensional properties may lead to unknown changes in fluid flow throughthe fluid delivery channel. Due to this variability, it is necessary toadjust the control of the pump to provide a consistent volume regardlessof the dimensional properties of the fluid delivery channel.

FIG. 4 depicts an illustrative automated fluid delivery system controlscreen according to some embodiments. As shown in FIG. 4, an automatedfluid delivery system control screen 405 may be configured to displayfluid delivery information such as the amount of available medical fluid420, requested medical fluid properties 410, and patient information415. The embodiment depicted in FIG. 4 is for an automated fluiddelivery system, such as an automated infusion system, configured todeliver a radiopharmaceutical to a patient. As such, the medical fluidinformation 420 may comprise information about the volume of theradiopharmaceutical and any fluids being combined therewith, therequested fluid properties 410 may comprise the requested radioactivity,and the patient information 415 may comprise the patient weight. Thecontrol screen 405 may provide one or more functions to an automatedfluid delivery system operator, such as system preparation 425,procedure information 430 and patient preparation 435. In addition,various other fluid delivery process control functions and informationmay be presented to an operator through the control screen 405, such asfunctions to start or stop the process, access data, and/or verify theconfiguration of the process.

According to some embodiments, the control screen 405 may be presentedon a display device operatively coupled with a computing device incommunication with the automated fluid delivery system, such as thecomputing device 110 and the fluid delivery apparatus 105 depicted inFIG. 1. The control screen 405 may be in communication with or may be acomponent of control software configured to operate the automated fluiddelivery system and/or components thereof (e.g., the pump and/or pumpcontroller).

It is important to ensure that a patient receives a proper dose of themedical fluid during the fluid delivery process. As such, the control ofthe fluid delivery pump should be established before the patient beginsto receive the medical fluid through the automated fluid deliverysystem. According to some embodiments, adjustment of the operation ofthe fluid delivery pump may be managed through the control softwareconfigured to operate the automated fluid delivery system and/orcomponents thereof. The operation of the fluid delivery pump may need tobe adjusted, for instance, due to variations in the dimensionalproperties of the fluid delivery channel. Embodiments provide thatadjustments to the operation of the fluid delivery pump may beimplemented when the fluid delivery channel is being primed with themedical fluid, such as through the patient preparation 435 functionavailable from the control screen 405. Priming allows the fluid deliverychannel to be pre-filled with fluid before injection, preventingunwanted air from being introduced into the patient's vasculature.

In an embodiment, the fluid delivery pump may be a peristaltic pump usedto deliver a radiopharmaceutical to a patient through the automatedfluid delivery system. Illustrative and non-restrictive examples ofradiopharmaceuticals include ⁶⁴Cudiacetyl-bis(N4-methylthiosemicarbazone) (e.g., ATSM or Copper 64),¹⁸F-fluorodeoxyglucose (FDG), ¹⁸F-fluoride,3′-deoxy-3′-[¹⁸F]fluorothymidine (FLT), ¹⁸F-fluoromisonidazole (FMISO),gallium, technetium-99m, indium-113m, strontium-87m, and thallium.

The control software may be configured to turn the rotor a specifiednumber of whole or partial rotations to displace a specified volume(e.g., an aliquot) of the radiopharmaceutical. The number of whole orpartial rotations determined by the control software may be based on oneor more pump coefficients, such as a volume-per-revolution coefficient.In another embodiment, the control software may be configured to operatethe pump for a specified time based on a volume-per-time coefficient asthe pump coefficient. The radioactivity of any particular volume of theradiopharmaceutical may be measured along the path of the fluid deliverychannel using one or more sensors (such as sensors 140 depicted in FIG.1). Non-limiting examples of sensors include silicon diodes, silicon PINdiode radiation sensors, avalanche diodes, scintillators,photomultipliers, solid state crystals, semiconductors, Geiger tubes,ionization-chamber radiation detectors, silicon photodiodes,microdischarge-based radiation detectors, sodium iodide crystalradiation detectors, bismuth tri-iodide crystal radiation detectors, orcadmium tellurium and cadmium zinc tellurium semiconductor crystalradiation detectors, and combinations thereof.

The peristaltic pump may rotate the specified number of rotations, forexample, when priming the fluid delivery channel, to displace a volumeof the radiopharmaceutical into the fluid delivery channel. The aliquotof radiopharmaceutical displaced in the fluid delivery channel may bemeasured for total radioactivity. The radioactivity of theradiopharmaceutical stored in the medical fluid source may be receivedby the control software. For example, the medical fluid sourceradioactivity may be measured by a sensor, may be entered into thecontrol software by an operator, and/or may be determined by a formula(e.g., based on the radioactivity when delivered to the medical facilityand the time between delivery and infusion). If the activity of theradiopharmaceutical in the medical fluid source from which the aliquotwas extracted is known, then the total radioactivity in the aliquot maybe used to determine the aliquot volume. The calculated volume of thealiquot may be compared with an expected volume by the control software.The control software may then rescale the value for thevolume-per-revolution parameter according to the measured radioactivityof the aliquot.

According to embodiments, the process for determining the propervolume-per-revolution parameter may be performed for each fluid deliverychannel set, may be performed multiple times to determine a statisticalaverage, and/or may be performed before each new patient.

The control software may have use default pump coefficient (C_(d)), forexample, based on operating the fluid delivery pump under standardconditions. In one embodiment, C_(d) may be used to calculate acorrected pump coefficient (C_(c)) using the measured radioactivity ofthe radiopharmaceutical (M), standard pump movement (K) and assayconcentration (A) according to the following: C_(c)=M/(K×A). Embodimentsprovide that C_(c) and C_(d) may represent volume-per-revolutionparameters, for instance, having units of milliliters (mL)/revolution, Mmay have units of mCi, and A may have units of mCi/mL. In anotherembodiment, C_(c) may be determined by applying an alpha (a) filtermechanism to C_(d) instead of through direct measurement.

The variable K may have units that depend on the type of fluid deliverypump. For example, for a peristaltic pump, the units of K may have unitsof pump revolutions. In another example, K may have units of encodercounts or linear travel distance for a syringe pump. In essence, C_(c)may be configured as a measure of a volume/native pump movement metricused to command the pump. In a non-limiting example, a target dose T maycomprise the target dose amount wherein dosing is volume based, and thepump may be commanded to pump a certain volume in mL using the followingequation: pump revolutions=C_(c)(mL/rev)*[T (mCi)/A (mCi/mL)]. Thisprocess may provide an intermediate estimate of volume for fluidaccounting, which may rely on an accurate estimate of A for proper dosemeasurement. According to some embodiments, C_(c) may be measureddirectly when setting up a fluid delivery system using a small number ofknown motor movements as opposed to assuming a default value C_(d) andapplying corrections after a dose intended for patient fluid deliveryhas already been extracted.

In an embodiment, an alpha filter may be used with multiple measurementsto arrive at a final coefficient. For instance, instead of assigningC_(c)=M/K×A directly, C_(c)[n] may be set asC_(c)[n]=C_(c)[n−1]*(1−alpha)+alpha*M/K×A, where alpha is a valuebetween 0 and 1. This process may converge slower, but may prevent asingle measurement from causing the measurement system to destabilize.In general, the process may operate to average multiple readings intothe final corrected coefficient instead of making a direct assignmentbased on a single reading.

As described herein, embodiments may provide for activity-based dosingas opposed to conventional volume-based dosing. An automated fluiddelivery system may be configured to tune dosage volumes based onconcentration measurements. In an embodiment, dosing measurements maycomprise a plot of activity ingress to achieve optimal amount of dose inthe fluid delivery channel and as a visual indication of thesemeasurements, for instance, for fault diagnosis. For example,T=(C_(d))(K)(A) and M=(C_(c))(K)(A) and, therefore, T=C_(d)/C_(c). Thefollowing may be formulated based on the foregoing calculations:C_(c)=((M)(Cd))/T=((M)(Cd))/((Cd)(K)(A)).

For activity based dosing, C_(c) may be measured during the initialconcentration check as C_(c)=M/K. In an embodiment, M/K may have unitsof mCi/rev. In another embodiment, the activity measurements may be MBq,mCi, or other concentration units and the units of native motor motionmay depend on the type of pump and control mechanism, as describedabove. For example, M/K may have units of mCi/millimeter for a syringepump. In activity based dosing, the motor may be commanded to moveT/C_(c) revolutions to extract the proper dose amount, allowing foraccurate dosing without an accurate or less accurate estimate of sourceconcentration A. In a non-limiting example, the coefficient may be tunedusing the process C_(c)(new)=C_(c)(current)*M/T, where M is the measuredactivity and T is the target activity. This correction process may beapplied when dosing regardless of the dosing method (e.g., regardless ofthe units of C_(c)).

FIG. 5 depicts a flow diagram of a method of dispensing a fluidaccording to an embodiment. As shown in FIG. 5, a fluid may be forced505 from a fluid source toward a dispensing element through a fluiddelivery channel using a pump. For example, a peristaltic pump mayrotate a specified number of rotations to move an aliquot of a medicalfluid into a fluid delivery channel from a fluid source. In anembodiment, the specified number of rotations may be enough to move asample volume of the fluid into the fluid delivery channel and notenough to dispense the fluid to a patient. The medical fluid maycomprise a radiopharmaceutical, such as a contrast agent for a nuclearimaging procedure. A processor may receive 510 a sample value of aproperty of the fluid in the fluid delivery tube. For aradiopharmaceutical, the sample value may comprise the radioactivity ofthe aliquot in the fluid delivery channel as measured by one or moresensors accessible by the processor. A source value of the property forthe fluid source may be received 515 by the processor. The source valuemay be obtained from the fluid source through various methods, includingthrough measurement by a sensor, data entry by an operator, calculationbased on properties of the fluid source, and combinations thereof.

The processor may determine 520 a sample volume of the fluid in thefluid delivery channel based on a comparison of the sample value and thesource value. For instance, the radioactivity of the fluid source may becompared with the radioactivity of the fluid in the fluid deliverychannel to determine the volume of the fluid in the fluid deliverychannel. Operation of the pump may be controlled 525 to dispense apredetermined dose of the fluid based on comparing the sample volumewith an expected volume. For example, the comparison of the samplevolume and the expected volume may be used to adjust, calibrate, orotherwise correct the operation of the pump to dispense a predetermineddose of the fluid to a patient. For instance, automated fluid deliverysystem control software may be configured to rotate the pump rotor Xtimes to dispense a predetermined amount (e.g., mL, mCi, etc.) of thefluid to achieve the predetermined dose. The amount of the fluidrequired for the dose may depend on various factors, such as whether thedose is determined by concentration, radioactivity, and the like. Forexample, for a radiopharmaceutical, the dose may be an amount ofradioactivity, while for a medicine in solution, the dose may be aparticular volume (e.g., mL) of the fluid. The comparison of the samplevolume with the expected volume may reveal that rotating the pump rotorX times may dispense more/less than the predetermined dose. As such, thenumber of times to rotate the pump rotor may be adjusted by the controlsoftware to rotate the pump rotor the correct number of times (e.g.,X×adjustment coefficient) to dispense the predetermined amount of thefluid.

FIG. 6 depicts a block diagram of exemplary internal hardware that maybe used to contain or implement program instructions, such as theprocess steps discussed above in reference to FIG. 5, according to anembodiment. A bus 600 serves as the main information highwayinterconnecting the other illustrated components of the hardware. CPU605 is the central processing unit of the system, performingcalculations and logic operations required to execute a program. CPU605, alone or in conjunction with one or more of the other elementsdisclosed in FIGS. 1 and 6, is an exemplary processing device, computingdevice or processor as such terms are using in this disclosure. Readonly memory (ROM) 610 and random access memory (RAM) 615 constituteexemplary memory devices.

A controller 620 interfaces with one or more optional memory devices 625to the system bus 600. These memory devices 625 may include, forexample, an external or internal DVD drive, a CD ROM drive, a harddrive, flash memory, a USB drive or the like. As indicated previously,these various drives and controllers are optional devices.

Program instructions, software or interactive modules for providing thedigital marketplace and performing analysis on any received feedback maybe stored in the ROM 610 and/or the RAM 615. Optionally, the programinstructions may be stored on a tangible computer readable medium suchas a compact disk, a digital disk, flash memory, a memory card, a USBdrive, an optical disc storage medium, such as a Blu-ray™ disc, and/orother recording medium.

An optional display interface 630 may permit information from the bus600 to be displayed on the display 635 in audio, visual, graphic oralphanumeric format. Communication with external devices may occur usingvarious communication ports 640. An exemplary communication port 640 maybe attached to a communications network, such as the Internet or anintranet. Other exemplary communication ports 640 may comprise a serialport, a RS-232 port, and a RS-485 port.

The hardware may also include an interface 645 which allows for receiptof data from input devices such as a keyboard 650 or other input device655 such as a mouse, a joystick, a touch screen, a remote control, apointing device, a video input device and/or an audio input device.

It will be appreciated that various of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. It will alsobe appreciated that various presently unforeseen or unanticipatedalternatives, modifications, variations or improvements therein may besubsequently made by those skilled in the art which alternatives,variations and improvements are also intended to be encompassed by thefollowing claims.

What is claimed is:
 1. A system for dispensing a fluid, comprising: asyringe pump configured to force an aliquot of a medical fluid from afluid source into a fluid delivery channel; at least one optical sensorconfigured to measure a sample value of a property of the aliquot,wherein the property is selected from the group consisting ofconcentration, salinity, optical properties, analyte concentration andcombinations thereof; a processor in communication with the syringe pumpand the at least one optical sensor; and a non-transitory,computer-readable storage medium in operable communication with theprocessor, wherein the computer-readable storage medium contains one ormore programming instructions that, when executed, cause the processorto: receive the sample value of the property of the aliquot, receive asource value of the property for the fluid source, determine a samplevolume of the aliquot based on a comparison of the sample value and thesource value, determine a pump coefficient based on a comparison of thesample volume with an expected volume, wherein the pump coefficient isconfigured to indicate a volume of the medical fluid forced into thefluid delivery channel per unit, and control operation of the syringepump to dispense a predetermined dose of the medical fluid based on thecomparison of the sample volume with the expected volume.
 2. The systemof claim 1, wherein the property comprises an optical property.
 3. Thesystem of claim 1, wherein the property comprises an analyteconcentration.
 4. The system of claim 1, wherein the pump coefficientcomprises a volume-per-time coefficient.
 5. The system of claim 1,wherein the pump coefficient comprises a volume-per-linear traveldistance coefficient.
 6. The system of claim 1, wherein the one or moreprogramming instructions, that, when executed, cause the processor tocontrol operation of the syringe pump further comprise one or moreprogramming instructions that, when executed, cause the processor tocontrol operation of the syringe pump using the pump coefficient.
 7. Thesystem of claim 1, wherein the one or more programming instructionsthat, when executed, cause the processor to control operation of thesyringe pump further comprise one or more programming instructions that,when executed, cause the processor to adjust the pump coefficient tocorrespond with dispensing the predetermined dose.
 8. The system ofclaim 1, wherein the sample volume of the aliquot is affected by atleast one dimensional property of the fluid delivery channel.
 9. Thesystem of claim 8, wherein the at least one dimensional property of thefluid delivery channel at a first section of the fluid delivery channelis different from the at least one dimensional property at a secondsection of the fluid delivery channel.
 10. The system of claim 9,wherein the first section of the fluid delivery channel is made of afirst material and the second section of the fluid delivery channel ismade of a second material.
 11. The system of claim 10, wherein adifference between at least one dimensional property of the firstsection and the second section of the fluid delivery channel isdetermined by different characteristics of the first material and thesecond material.
 12. The system of claim 8, wherein the at least onedimensional property of the fluid delivery channel is selected from thegroup consisting of an inner diameter of the fluid delivery channel, anouter diameter of the fluid delivery channel, a thickness of a wall ofthe fluid delivery channel, and combinations thereof.
 13. The system ofclaim 8, wherein the at least one dimensional property varies along alength of the fluid delivery channel.
 14. The system of claim 1, whereinthe processor adjusts the control of the syringe pump to provide aconsistent volume delivered regardless of a dimensional property of thefluid delivery channel.
 15. The system of claim 1, wherein the expectedvolume comprises a volume of the medical fluid forced by the syringepump under standard conditions.
 16. The system of claim 1, wherein thenon-transitory, computer- readable storage medium comprises a remoteoperated touch screen.
 17. A method of dispensing a medical fluid,comprising: providing a syringe pump configured to force an aliquot of amedical fluid from a fluid source into a fluid delivery channel;receiving, by a processor, a source value of an optical property for thefluid source and a sample value of the optical property for the aliquotmeasured by at least one optical sensor; determining, by the processor,a sample volume of the aliquot based on a comparison of the sample valueof the optical property and the source value of the optical property;determining, by the processor, a pump coefficient based on a comparisonof the sample volume with an expected volume, wherein the pumpcoefficient is configured to indicate a volume of the medical fluidforced into the fluid delivery channel per linear distance traveled; andcontrolling, by the processor, operation of the syringe pump to dispensea predetermined dose of the medical fluid based on a comparison of thesample volume with the expected volume.
 18. The method of claim 17,wherein the pump coefficient comprises a volume-per-time coefficient.19. The method of claim 17, wherein the pump coefficient comprises avolume-per-linear travel distance coefficient.
 20. The method of claim17, wherein controlling operation of the syringe pump further comprisescontrolling the syringe pump using the pump coefficient.